A new architecture for cyber maps: An internet-oriented next-generation spatial information service System
Problems of data type:
If spatial information is supplied in bit-map format, it is impossible to support hyper retrieval
functions. Therefore, in order to support interoperable retrieval from information supplied from
Table 1 Progress in information service methods under internet communication environment
other WWW servers, information should be handled in standard formats like HTML or GIF. This
Cm be summarized as:
Problem 1) How do we make a standard vector-based system under an intemet communication
environment?
Problems of spatial information management method:
One characteristic of spatial information is that records are variable in length and have adjacency
relationships with each other. Therefore, an RDBMS that supports a database server in a second-generation
system cannot manage this kind of spatial data effectively.
Problems 2) How can we provide an effective unified management method for spatial databases
and attribute databases?
What are the problems in making mobile retrieval practical. There are already many kinds of
navigation systems, which are practical applications of a geographical information service.
Almost all of these systems use off-line system composition, overlaying locations obtained from
Global Positioning Satellites onto a map retrieved from a CD-ROM. Therefore, this type of
information service is not suitable for various office-work systems that demand online database
retrieval, so there are many problems as follows.
Problems for information service style:
The quantity of information stored in a map database is very large, and wireless communication
is not fast enough to handle it. Moreover, if PDAs are used as web terminals, their displays are
not big enough and their graphics performance is very poor. They will not be able to handle the
heavy processing or the resolution that ordinwy web terminals can. This can be summarized as:
Problem 3) How can we provide the most effective information service to match the capabilities
of each terminal?
Problems for nomadic Retrieval:
One drawback of wireless communication is that connections are frequently broken when a user
moves, depending on the level of noise or location of repeaters. So when a user accesses the
service, he/she should be offered the choice of canceling past database transactions or continuing
suspended ones. This can be summarized as:
Problem 4) How can we achieve nomadic database retrieval?
